<!DOCTYPE html>
<html>

<head>
	<meta charset="utf-8" />
	<title></title>
	<script src="./../vue.js/vue.js"></script>
</head>

<body>
	<div id="app">
		{{ message }}
	</div>
</body>

<script>
	var vm = new Vue({
		el: "#app",
		data: {
			message: "hello vue."
		}
	});

	console.log(vm.$data); //{__ob__: Observer}
	console.log(vm._data); //{__ob__: Observer}
	console.log(vm.$data === vm._data); //true

	//三种方式都可以访问到message
	console.log(vm.$data.message); //hello vue
	console.log(vm._data.message); //hello vue
	console.log(vm.message); //hello vue

	console.log(Vue.prototype)
	console.log(vm);
</script>

</html>